This invention relates in general to devices for improving golf swings and, more particularly, to a device for measuring and analyzing balance shifts and weight shifts during a golf swing.
A wide variety of teaching and training aids have been designed over the years to aid individuals in developing a golf swing of optimum power and accuracy. These devices have purposes such as improving stance, backswing, hand or head position, follow through and the like. In an optimum golf swing for most right-handed persons, weight which is initially evenly divided between the feet when the ball is addressed, shifts to the right foot during the backswing, then during the downswing is returned to the left foot at impact and continues to shift to the left foot during follow through. For most golfers, the ideal combination of power and accuracy has been found to occur when weight is shifting to the left foot at the instant of impact.
It is, of course, difficult if not impossible, for either the golfer or an observer, such as a golf teaching professional, to determine whether correct weight shift has occurred during a swing. Also, undesirable shifts of weight between the golfer's heels and toes may occur during the swing which, again, is difficult for a golfer or observer to recognize.
Attempts have been made to provide devices which indicate weight shift in a visible manner. For example, Kretsinger in U.S. Pat. No. 3,169,022 describes a system in which the golfer stands on two pads and swings a club at a simulated golf ball. Each pad contains a weight responsive variable capacitor which sends a signal to a display in the form of a row of indicator lamps. Lamps will light from the center to each side in accordance with the weight on each pad. A sound responsive pick-up device freezes the light display at the moment of club impact with the ball. The display only shows the degree of weight imbalance between the feet at moment of impact and does not show weight shift at backswing or follow through. The indication cannot be saved for convenient comparison to the results with other swings. Since results are affected by the user's weight, it must be readjusted for different users and will probably be inconsistent from one use to the next by the same person. The device is incapable of analyzing an entire swing and of measuring toe to heel weight shifts. Further the device does not provide digital information and does not supply "quantifiable" data.
Another golf swing practice device is described by O'Donnell in U.S. Pat. No. 3,994,501. Two opposed blades are hinged at a midpoint and extend in opposite directions, with the distal ends elevated by compression springs. A golfer stands with one heel on each raised end. A switch turns on a light when the blade is depressed by the golfer's weight. When a right-handed golfer swings, if the swing is correct and left heel is raised during the backswing and weight has returned to the left heel at impact a light will turn on. While possibly of some use, this crude indication does not indicate correctness of the follow through and does not analyze the entire swing. No indication of swing quality is saved for comparison with later swings or ideal swings.
Thus, there is a continuing need for systems for fully analyzing golf swing from the backswing, through impact, to the follow through. For effective teaching, there is a need for a way to compare the results of each swing with earlier and later swings.